The invention here involved has reference to a drill bushing of the type where one part is stationarily mounted as on a drill jig, and the other part portably mounted upon the power tool, the portable part being provided with coolant passages to direct a coolant liquid from an appropriate source to the tool where the cutting edge of the tool is in engagement with the work piece. There is a special arrangement of coolant passages in the portable part attached to the power tool which is such that the coolant passes entirely within the stationary part without the need for any portion of the coolant passages to be in the stationary part. The movable part is of such character that it can be reversed into disengagement from the stationary part, and thereafter immediately directly driven into engagement with a succeeding stationary part at a different location.
Drill bushings have been widely used in various applications to radially and axially guide drills and reamers. Various existing bushing designs have been proposed to improve cutting efficiency. In the metal working industries, applying coolant to the cutting tool in a proper place has become critical in most drilling and reaming operations. Accordingly, addition of a coolant port on the portable part of the device should be one to allow passage of liquid coolant directly through appropriate orifices of the bushing shank directly to the cutting edge of the tool. It is also important to have the functioning parts quickly engageable and re-engageable so that the operation can be shifted from one location to another without delay in the manufacturing process.
It is therefore among the objects of the invention to provide a new and improved coolant device for portable power feed drills which provides an appropriate continuous flow of coolant directly to the cutting edge of the tool.
Another object of the invention is to provide a new and improved coolant device for drill bushings of a character such that the coolant is fed constantly to the work piece, whereby to serve also as a lubricating fluid to help dissipate friction heat and to extend tool life.
Further among the objects of the invention is to provide a new and improved coolant device for portable power-fed cutting tools comprising cooperating parts one of which being a relatively simple structure can be jig mounted in multiple numbers in stationary position and the others of which, being a portable structure, can be mounted on the powerful tool and readily shifted from one stationary structure to another.
Still another object of this invention is to provide a new and improved coolant device comprising cooperating parts wherein one of such parts is a relatively simple jig mounted structure and the other is a portable structure carrying all of the lubricant passages in an arrangement wherein the portable structure passes coolant through the stationary structure directly to the cutting edge of the tool, the direction of flow being a function of the portable structure.
Also included among the objects of the invention is to provide a new and improved coolant device of portable character wherein the attachment to the coolant supply line provides a 360 degree swivel so that the tool and associated parts can be oriented in any direction with respect to the work.
Included further among the objects of the invention is to provide a new and improved efficient and dependable portable coolant device capable of directing a continuous flow of coolant to the cutting edge sufficiently well directed so that the force of the coolant flow is capable of forcing chips away from the work piece.
The objects include also such a coolant device capable of constant feed of coolant to the cutting edge in order to dissipate heat and accordingly extend the tool life, the coolant being made to serve as a lubricant whereby galling is reduced, as is also the dulling effect on the cutting edge of the tool, the result of which is an increase in surface finish and reduction in rejection rates in addition to adding to tool life.
With these and other objects in view, the invention consists of the construction, arrangement, and combination of the various parts of the device serving as an example only of one embodiment of the invention, whereby the objects contemplated are attained, as hereinafter disclosed in the specification and drawings, and pointed out in the appended claims.